Attachment for gun barrels



April I949- E. BRISTOW 2,466,203

ATTACHMENT FOR GUN BARRELS I Filed Aug. 25, 1947 2 Sheets-Sheet l E. BRISTOW ATTACHMENT FOR GUN BARRELS April 5, 1949.

2 Sheets-Sheet 2 Filed Aug. 25, 1947 A Ila may:

Patented Apr. 5, 1949 UNITED STATES i N T 'FFI- 'CE ATTACHMENT FOR- GUN. BARRELS Earl Bristow, Harrisburg, 111., assign'or of one-half to Bil 1r Ghent, Harrisburg; 111.

Application August 25, 1947, Serial No.- 770,351

4'Glaims.

1 The I present invention relates" to' attachments for gun" barrels and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

' It is an object-of the inventionto provide an attachment fo'rgun barrels whichis simple and inexpensive in construction, easyto operate and "yet eificient and effective in its use.

vision of semi-automatic means for re-setting a device ofthe character set forth to normal, that is to say, inoperative position upon the firing of each round.

' Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawing, in which:

Figure l is a side elevational view of an embodiment of the invention mounted upon a shot- Figure 2 is an enlarged fragmentary bottom plan view of the device looking in the direction of the arrows 22 in Figures 1 and 3,

Figure 3 is a side elevational view of Figure 2,

Figure 4 is an enlarged sectional View taken along line 44 of Figure 3,

Figure 5 is a sectional view taken along line 55 of Figure 4,

Figure 6 is a sectional view taken along line B-6 of Figure 4,

Figure '7 is an enlarged sectional View taken along line 1-4 of Figure 2, and

Figures 8 and 9 are perspective views of elements of the invention.

Referring more particularly to the drawings, there is shown therein a shotgun l having a conventional stock ll, trigger l2 and barrel [3.

Adjacent the outer end of the barrel I3 there is threaded a retaining collar 14 by means of inwardly extending threaded portions [5. A series of fingers IE, each of which is arcuate in transverse cross section and each of which is provided with side recesses i1 adjacent its rear end, are adapted to be held upon the barrel by means of a retaining collar, which fits snugly about the fingers and has its threaded bosses l l3 adjacent the finger: r p 2 passing through openings formed by registering recesses ll of the fingers.

The fingers are relatively thin at the rear thereof and become increasingly thicker toward'their front'ends.

'Surmounting the fingers I'B between the "forward ends thereof and'the retaining collar i4 is a slidably mounted actuating ring l8 into the lower rear side-of whichis threaded, as indicated at i9, a rearwardly extending rod 20 which terminates in anintegrallyformed finger. eg

A clamp member 22 is mounted-on thebarrel Therod 20 is adapted to pass through an opening"23 in-the lower portion of the collar l4 and-an opening '24 in the lower portion ofthe clamp'm'ember 22.

A tension spring 25 is fastened in an opening in the rod 20, as indicated at 26, and'has its *other'end fastened in an opening in the clamp member 22, as shown at'21.

A fi'ontsight 28 is affixed in the-upper side of the'retaining collar i4 and a housing29-ior 'the'rod'2i3 andspring25 is" fastened tot-haunder'side' of'the retaining collar byscrews3fl or the like and by a latch member 3! carriedby the clamping member 22.

The operation of the device is quite simple. If it is desired to use full bore, the finger grip 2| is pulled rearwardly thus causing the actuating collar H? to move rearw-ardly and thereby allowing resiliency of the fingers [6 to cause them to be spread and spaced from each other at their forward ends. When a closer pattern of shot is desired, the finger grip 2| is moved forwardly causing the rod 20 and consequently the actuating collar I8 to move forwardly thus bringing the fingers closer together due to their increasing thickness in a forward direction. The bore is now restricted and thus restriction may be controlled by moving the actuating collar to whatever position desired. Frictional grip of the fingers with the ring holds the ring in a set position.

When the device is set for other than full bore and the gun is fired, the force of the charge passing through the fingers will tend to spread them, and as the fingers are spread they exert a cam action upon the ring and shift the ring rearwardly so that the spreading of the fingers is not prevented. The spring 25 exerts pull upon the rod 20 and urges it rearwardly so that the ring will be easily moved back along the fingers to its retracted position against the retaining collar [4, that is to say, in a full bore position.

While but one form of the invention has been 3 shown and described herein, it will be readily apparent to-those skilled in the art that many minor modifications may be made withoutdeparting from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A device of the character described comprising a retaining collar adapted to be threaded adjacent the outer end of a gun barrel, '2. plurality of fingers arcuate in cross section and, when assembled together forming a choke having a circular cross section and flaring towards its front end, said collar gripping rear portions of the fingers and having members passing through said fingers for preventing longitudinal movement Of the fingers upon the barrel and an actuatingring slidably mounted upon said fingers and adapted to gradually move the outer ends of said fingers toward each other as the ring is shifted forwardly along the fingers.

2. A device of the character described comprising a retaining collar of a diameter adapting it to be threaded upon the outer end portion of a gun barrel, a plurality of fingers arcuate in cross section and, when assembled together form ing :a choke having a circular cross section, said collar fitting tightly aboutrear portions of the fingers and having portions passing through openings in the fingers for retaining the fingers upon the barrel and having threaded engagement with the barrel, an actuating ring slidably mounted upon said fingers and serving to gradually move the outer ends of said fingers toward each other as the ring is shifted forwardly along the fingers.

3. A device of the character described comprising a retaining collar adapted tobe threaded adjacent the outer end of a gun barrel, a plurality of forwardly flaring fingers arcuate in cross section and, when assembled together forming a choke having a circular cross section, means for retaining said fingers upon the barrel by said retaining collar, an actuating ring fitting about the choke and slidably mounted upon said fingers and adapted to gradually move the outer ends 4. A device of the character described comprising a retaining collar adapted to be threaded adjacent the outer end of a gun barrel, a plurality of fingers arcuate in cross section and, when assembled together forming a choke having a circular cross section, means for retaining said fingers upon the barrel by said retaining collar, an actuating ring fitting about the choke and slidable along said fingers and serving to gradually move the outer ends of said fingers toward each other as the ring is slid forwardly along the fingers, a rearwardly extending rod affixed to said actuating ring, a grip formed at the rear end of said rod, a spring arranged to urge said rod. and actuating ring in a rearward direction and assist rearward movement of the ring when the fingers are flared by a charge of a passing shot and exerts a cam action upon the ring to force the ring rearwardly when the gun is fired, and a casing enclosing said rod and spring.

EARL BRISTOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 688,389 Cory Dec. 10, 1901 1,348,750 Schuster Aug. 3, 1920 2,134,238 Sedberry Oct. 25, 1938 Re. 20,958 White Dec. 27, 1938 2,270,592 Kitzmiller Jan. 20, 1942 

